Service application with learning capability

1. A method, performed by a target node classification entity, to control an application of a service providing module to a data packet flow, wherein the data packet flow is transmitted to a target node through a service network where the service providing module comprising a processor configured to apply a service to the data packet flow, the method comprising: receiving, from a flow classification entity, flow classification data about the data packet flow, the flow classification data including at least: a flow classifier classifying the data packet flow; a flow identifier uniquely identifying the data packet flow; and a target node address to which the data packet flow is addressed; classifying the target node based on the flow classifier contained in the received flow classification data, wherein a first service classifier is generated for the target node based on the flow classifier, and wherein the first service classifier indicates at least one service to be applied to the data packet flow; checking whether a classification database has to be updated based on the first service classifier of the target node, the classification database storing, for different target nodes, whether the at least one service has to be applied to data packet flows to the corresponding target node; and in response to determining that information in the classification database has to be updated: generating a flow command for a central flow controller which controls the data packet flows through the service network, wherein the generated flow command contains information that successive data packet flows in the service network transmitted to the target node address should be passed through the service network in accordance with the generated first service classifier of the target node; and transmitting the generated flow command to the central flow controller.

2. The method of claim 1 : further comprising updating the classification database, wherein the updating comprises storing the target node in the classification database in connection with the first service classifier as a second service classifier when the classification database does not contain information about the target node; and wherein the target node with the second service classifier is only stored in the classification database when the second service classifier of the target node indicates that the data packet flows through the service network to the target node do not follow a default service path through the service network.

3. The method of claim 2 : further comprising starting a timer when the classification database has been updated, wherein, when an expiration of the timer is detected, the central flow controller is informed to pass the data packet flows to the target node along the default service path through the service network.

4. The method of claim 2 : wherein, if the default service path through the service network indicates that the data packet flows to the target node should not be passed through the service providing module and if the first service classifier of the target node indicates that the data packet flows to the target node should pass the service providing module, the target node is stored in the classification database in connection with the second service classifier indicating that the data packet flows transmitted to the target node should be passed through the service providing module in the service network; and wherein the generated flow command transmitted to the central flow controller indicates that the successive data packet flows in the service network transmitted to the target node address should be passed through the service providing module.

5. The method of claim 2 : wherein, if the default service path through the service network indicates that the data packet flows to the target node should be passed through the service providing module and if the first service classifier of the target node indicates that the data packet flows to the target node should not be passed through the service providing module, the target node is stored in the classification database with the second service classifier indicating that the data packet flows transmitted to the target node should not be passed through the service providing module in the service network; and wherein the flow command transmitted to the central flow controller indicates that successive data packet flows in the service network transmitted to the target node address should not be passed through the service providing module.

6. The method of claim 1 , wherein the generated flow command contains information that a path for the data packet flow identified by the flow identifier through the service network should not be amended.

7. The method of claim 1 : further comprising updating the classification database, wherein the updating comprises updating a second service classifier stored in the classification database in connection with the target node in accordance with the first service classifier; and wherein the second service classifier in the classification database is only updated if both: the second service classifier, before the update, indicates that the data packet flows through the service network to the target node should not follow a default service path through the service network; and the first service classifier of the target node indicates that the data packet flows to the target node should follow the default service path through the service network.

8. The method of claim 7 , wherein the updating of the second service classifier stored in the classification database comprises removing the target node and the corresponding second service classifier from the classification database.

9. The method of claim 7 : wherein, if the default service path through the service network indicates that the data packet flows to the target node should not be passed through the service providing module and if the first service classifier of the target node indicates that the data packet flows to the target node should not be passed through the service providing module and if the second service classifier in the classification database indicates that the data packet flows transmitted to the target node should be transmitted through the service providing module, the second service classifier in the classification database is updated accordingly to indicate that the data packet flows to the target node should not be passed through the service providing module; and wherein the generated flow command transmitted to the central flow controller indicates that the successive data packet flows to the target node should not be transmitted through the service providing module anymore.

10. The method of claim 7 : wherein, if the default service path through the service network indicates that the data packet flows to the target node should be passed through the service providing module and if the first service classifier of the target node indicates that data packet flows to the target node should be passed through the service providing module and if the second classifier in the classification database indicates that the data packet flows transmitted to the target node should not be transmitted through the service providing module, the second service classifier in the classification database is updated accordingly to indicate that data packet flows transmitted to the target node should be passed through the service providing module; and wherein the flow command transmitted to the central flow controller indicates that the successive data packet flows to the target node should be transmitted through the service providing module again.

11. The method of claim 1 : further comprising determining whether the classification of the target node based on the first service classifier and a second service classifier stored in the classification database in connection with the target node both indicate that the data packet flows through the service network to the target node should not follow a default service path through the service network; and in response to the determining be in the affirmative, the second service classifier stored in the classification database is kept unamended and a timer indicating that the data packet flows to the target node should not follow the default service path through the service network is updated.

12. The method of claim 1 , wherein, in response to an expiration of a timer stored in the classification database in connection with a target node being detected: the target node is removed from the classification database, and the central flow controller is informed to pass the data packet flows to the target node along a default service path through the service network.

13. The method of claim 1 , wherein a plurality of flow classifiers are received for different data packet flows to the target node, and only if a predefined amount of the received plurality of flow classifiers indicate the same type of flow classifier, then: the first service classifier is generated for the target node; and the checking, whether the classification database has to be updated based on the generated first service classifier, occurs.

14. A target node classification entity configured to control an application of a service providing module to a data packet flow, wherein the data packet flow is transmitted to a target node through a service network where the service providing module comprising a processor configured to apply a service to the data packet flow, the target node classification entity comprising: a receiver configured to receive, from a flow classification entity, flow classification data about the data packet flow, the flow classification data including at least: a flow classifier classifying the data packet flow; a flow identifier uniquely identifying the data packet flow; and a target node address to which the data packet flow is addressed; processing circuitry configured to: classify the target node based on the flow classifier contained in the received flow classification data; generate a first service classifier for the target node based on the flow classifier, wherein the first service classifier indicates at least one service to be applied to the data packet flow; check whether a classification database has to be updated based on the first service classifier of the target node, the classification database storing, for different target nodes, whether the at least one service has to be applied to data packet flows to the corresponding target node; and in response to determining that information in the classification database has to be updated, generate a flow command for a central flow controller which controls the data packet flows through the service network, wherein the generated flow command contains information that successive data packet flows in the service network transmitted to the target node address should be passed through the service network in accordance with the generated first service classifier of the target node; and a transmitter configured to transmit the generated flow command to the central flow controller.

15. The target node classification entity of claim 14 : wherein the receiver is further configured to receive a plurality of flow classifiers for different data packet flows to the target node; and wherein the processing circuitry is configured such that, only if the processing circuitry determines that a predefined amount of the received plurality of flow classifiers indicates the same type of flow classifier, does the processing circuitry generate the first service classifier for the target node, and check whether the classification database has to be updated based on the generated first service classifier.

16. A method for controlling, performed by a central flow controller, data packet flows in a service network in which service providing modules comprising a processor configured to apply services to the data packet flows, wherein the data packet flows are transmitted through the service network to a target node based on a first service classifier of the target node, the method comprising: receiving, from a target node classification entity, a flow command, the flow command containing information that successive data packet flows in the service network transmitted to the target node should be passed through the service network in agreement with the first service classifier of the target node contained in the received flow command, wherein the first service classifier is comprised in the received flow command, wherein the first service classifier indicates at least one service to be applied to the data packet flows, and wherein the first service classifier is generated for the target node by the target node classification entity; determining, based on the received flow command, an updated path for the successive data packet flows to the target node in accordance with the received flow command; and programming forwarding elements in the service network which forward the data packet flows in the service network in such a way that the successive data packet flows to the target node follow the updated path.

17. The method of claim 16 : wherein the flow command contains a flow identifier and information that a path for the data packet flows identified by the flow identifier through the service network should not be amended; and wherein the forwarding elements in the service network are programmed in such a way that the path of the data packet flows through the service network identified with the received flow identifier remains unchanged.

18. The method of claim 16 , wherein, when the first service classifier received in the flow command indicates that the data packet flows to the target node should be transmitted through a service providing module: the updated path through the service network is adapted in such a way that the data packet flows to the target node pass the service providing module; and the forwarding elements are programmed in such a way that the successive data packet flows to the target node pass through the service providing module.

19. The method of claim 16 , wherein, when the first service classifier received in the flow command indicates that the data packet flows to the target node should not be passed through a service providing module: the updated path through the service network is adapted in such a way that the data packet flows to the target node bypass the service providing module; and the forwarding elements are programmed in such a way that the successive data packet flows to the target node bypass the service providing module.

20. The method of claim 16 : wherein a default path for the data packet flows through the service network exists; and wherein, if it is determined, based on the received first service classifier, that the data packet flows to the target node should not follow the default path and should bypass a flow classification entity, at least one forwarding element forwarding the data packet flows to the target node is instructed to forward a part of the data packet flows transmitted to the target node through the flow classification entity.

21. A central flow controller configured to control data packet flows in a service network in which service providing modules comprising a processor configured to apply services to the data packet flows, wherein the data packet flows are transmitted through the service network to a target node based on a first service classifier of the target node, the central flow controller comprising: a receiver configured to receive, from a target node classification entity, a flow command, the flow command containing information that successive data packet flows in the service network transmitted to the target node should be passed through the service network in agreement with the first service classifier of the target node contained in the received flow command, wherein the first service classifier is comprised in the received flow command, wherein the first service classifier indicates at least one service to be applied to the data packet flows, and wherein the first service classifier is generated for the target node by the target node classification entity; and processing circuitry configured to: determine, based on the received flow command, an updated path for the successive data packet flows to the target node in accordance with the received flow command; and program forwarding elements in the service network which forward the data packet flows in the service network in such a way that the successive data packet flows to the target node follow the updated path.

22. A computer program product stored in a non-transitory computer readable medium for controlling an application of a service providing module to a data packet flow, wherein the data packet flow is transmitted to a target node through a service network where the service providing module comprising a processor configured to apply a service to the data packet flow, the computer program product comprising software instructions which, when run on processing circuitry of a target node classification entity, cause the target node classification entity to: receive, from a flow classification entity, flow classification data about the data packet flow, the flow classification data including at least: a flow classifier classifying the data packet flow; a flow identifier uniquely identifying the data packet flow; and a target node address to which the data packet flow is addressed; classify the target node based on the flow classifier contained in the received flow classification data, wherein a first service classifier is generated for the target node based on the flow classifier, and wherein the first service classifier indicates at least one service to be applied to the data packet flow; check whether a classification database has to be updated based on the first service classifier of the target node, the classification database storing, for different target nodes, whether the at least one service has to be applied to data packet flows to the corresponding target node; and in response to determining that information in the classification database has to be updated: generate a flow command for a central flow controller which controls the data packet flows through the service network, wherein the generated flow command contains information that successive data packet flows in the service network transmitted to the target node address should be passed through the service network in accordance with the generated first service classifier of the target node; and transmit the generated flow command to the central flow controller.

23. A computer program product stored in a non-transitory computer readable medium for controlling data packet flows in a service network in which service providing modules comprising a processor configured to apply services to the data packet flows, wherein the data packet flows are transmitted through the service network to a target node based on a first service classifier of the target node, the computer program product comprising software instructions which, when run on processing circuitry of a central flow controller, causes cause the central flow controller to: receive, from a target node classification entity, a flow command, the flow command containing information that successive data packet flows in the service network transmitted to the target node should be passed through the service network in agreement with the first service classifier of the target node contained in the received flow command, wherein the first service classifier is comprised in the received flow command, wherein the first service classifier indicates at least one service to be applied to the data packet flows, and wherein the first service classifier is generated for the target node by the target node classification entity; determine, based on the received flow command, an updated path for the successive data packet flows to the target node in accordance with the received flow command; and program forwarding elements in the service network which forward the data packet flows in the service network in such a way that the successive data packet flows to the target node follow the updated path.